After failing to recruit a viable alternative to Donald Trump and already missing deadlines to register an independent candidate for president in states like Texas, the door has officially closed for the Never Trump crowd. Now, instead of enabling Hillary Clinton by attacking the presumptive Republican nominee, it is time for Never Trump to focus its attention and resources on keeping the Senate.

If Republican donors and voters do not like Donald Trump, they should want control of Congress to serve as a check on his potential presidency. They should also want a Republican Congress to work alongside Donald Trump on critical issues like repealing Obamacare, rolling back job-killing regulations and enacting pro-growth policies to revive our struggling economy. With Republicans defending 24 Senate seats, seven in states President Obama won in 2008 and 2012, there is plenty of work to be done.

The University of Virginia's Institute of Politics' Larry Sabato has ranked states Republicans are defending like Florida, Illinois, New Hampshire, Ohio, Pennsylvania and Wisconsin as either a "Toss Up" or "Lean Democratic." There are also potential pick up opportunities for Republicans in states like Colorado and Nevada, and Sen. Chuck Grassley appears to be favored for reelection in Iowa. The Democratic Party needs to gain only four or five seats, depending on the outcome of the presidential election, to take back control of the Senate. That means the Republican Party has some serious work to do. But it can be done.

While the mainstream media likes to discuss the drag they believe Donald Trump will have on down ballot races, Hillary Clinton is a poison pill. The Democratic Party in the difficult position of having to defend one of the most unpopular candidates in history. The party also owns policies that have led to the loss of 13 Senate seats, 69 House seats, 12 governorships, 30 state legislative chambers and more than 900 state legislative seats during President Obama's time in office. These Democratic candidates will be forced to defend the unpopular Iran deal, efforts to close Guantanamo Bay and bring terrorists to American soil, Obamacare, and economic policies that have left the middle class behind.

The Democratic Senatorial Campaign Committee has also been forced to spend millions of dollars to drag hand-selected candidates like Ted Strickland in Ohio, Patty Judge in Iowa, and Katie McGinty in Pennsylvania through their primaries and to the finish line. In Florida, preferred candidate Patrick Murphy is still fighting for survival in a contested primary against Alan Grayson.

Republicans are well positioned to win in states like Florida, where they won all four statewide races in 2014 by an average of over 12 percentage points and won the last four gubernatorial elections. They will hold strong in states like Illinois, where Sen. Mark Kirk has never lost an election and has consistently outperformed the top of the ticket. The Republican Party will likely keep Iowa, where Sen. Chuck Grassley has an approval rating of +22 percent. In Ohio, Republicans have swept all 6 statewide elected positions since 2010 and Sen. Rob Portman won his 2010 race by 18 points. In New Hampshire, Sen. Kelly Ayotte has consistently held a lead in public polling. And Sen. Ron Johnson in Wisconsin is facing a rematch of the 2010 race that he won.

While much attention is being paid to the presidential election, it is critical for the Republican Party, particularly the most vocal critics of Donald Trump, to focus on retaining the Senate majority. For it is on the Senate that Republicans' 2016 electoral fortunes may ultimately ride.

Lisa Boothe is a contributing columnist for The Washington Examiner and president of High Noon Strategies.